A99
Prognostic significance of periodic acid-schiff-positive patterns in kidney cancer
Amalia Vartanian, Eugenia Stepanova, Mikhail Lichinitser
Russian Cancer Research Center, Moscow, Russia
Background
Recent advances in the understanding of the pathogenesis of renal cell carcinoma (RCC) have identified angiogenesis as a key factor in the development of disease and VEGF was definitely evolving as one of the most important independent prognostic parameters in RCC. The data obtained in our laboratory indicated that VEGF expression in highly aggressive and metastatic tumors might have dual functions: direct influence on tumor cell growth and involvement in tumor vasculogenic mimicry (VM) the formation of highly patterned vascular channels by tumor cells – similar to embryonic vasculogenesis - that stains positive with periodic Acid-Schiff (PAS) reagent. To date, there is little data on the functional role of VM.
Results
In this study, we explored whether kidney cancer could contain tumor cells lined channels. We studied 46 patients with clear cell renal cell carcinoma (cRCC) treated at the Russian Cancer Research Center.
The data revealed that tumor sections from high-stage, high-grade cRCC contain back-to-back closed loops encircling small cluster of tumor cells, networks (at least three loops), parallel or straight PAS-positive patterns. Next, we studied the significance of PAS-positive patterning in cRCC on DFS. Survival probabilities were determined by Kaplan-Meier estimates, and prognostic factors were evaluated by multivariate analysis. In this relatively small sample of patients the detection of the PAS-positive back-to-back closed loops or networks was associated with a decrease in disease-free outcome.
Conclusion
To our knowledge, this is first description of VM in kidney cancer. The data obtained advance our present thinking concerning the vascularization of kidney cancer and may offer new insights for consideration in kidney cancer diagnosis and treatment strategies.
